Low noise output stage for oversampling audio DAC

This paper presents a low noise output stage of oversampling audio digital-to-analog converter (DAC). The proposed glitchless switched capacitor DAC (GSC-DAC) eliminates the penalty of a constrained signal range and a signal distortion caused by return-to-zero signals in SC-DAC that is an essential part in order to convert the digital signal into the analog signal. By using a track and hold circuit and deglitching method in GSC-DAC, the low noise is efficiently achieved. The results of post layout simulation show the noise performance improvements of 21dB on average of SNR, SNDR, SFDR and THD in comparison with the absence of the proposed techniques.